Advertising display apparatus with precise rotary drive

ABSTRACT

An advertising display apparatus with precise rotary drive includes a programmable stepper motor positively coupled to a pair of eccentric drives. Rotation of the eccentric drives moves a film sheet containing discrete images formed from corresponding sets of pixels through a closed loop path across a platen stopping at precise dwell points. At each dwell point, a set of pixels register with a plurality of apertures within an overlying grid sheet and are illuminated by a light source within the apparatus to display the image.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an apparatus and method forsequentially displaying multiple high resolution images in a singledisplay and more particularly to an improved drive means for such adisplay apparatus.

2. Description of the Prior Art

A great demand has arisen for display advertising using animation andmultiple advertisements at individual popular display locations therebyenabling a number of advertisers to benefit from a single location.Numerous different methods and devices have been proposed for preparingand displaying such advertisements. Many such devices involve relativelyunwieldy mechanical elements driven by complex drive mechanisms whichoften generate noise at an annoying level. In addition to the expense oforiginal manufacture, the user is often faced with expensivemaintenance.

Typically, these devices are used in public retail outlets or otherpublic locations. It is desirable to display multiple advertising imageswherein the exchange from one image to another is nearly instantaneousthereby enabling the sequential display of different images in a mannerwhere the exchange is imperceptible to the human eye from a distance ofseveral feet and beyond from the display. Such a sequential displaytends to draw and hold a viewer's attention without an annoyingperception that one view is being broken up and another assembled.

Display devices have included transparency sheets having images thereonilluminated by back lighting through an overlay mask which blocks theback lighting from illuminating certain areas of the transparencysheets. Animated displays have included a grid having alternate opaqueand transparent strips and a photographic transparency on which discreteimages are arranged in parallel image strips which are moved relative toone another to give the impression of animation. The image strips of thephotographic transparency are wider than the transparent strips of thegrid. When the center lines of a set of image strips are aligned withthe transparent lines of the grid, only three fifths of each strip isvisible. Thus, some image information is lost. A device of this type isshown, for example, in U.S. Pat. No. 3,742,631 to Hasala. Because theimage strips are only moved laterally, for a display of more than twoimages from one composite mosaic, the relative travel between the maskof transparent sheets must be considerable adding to the noise level andgenerating unwanted movement likely to distract the viewer.

Display devices have also included a grid moved in a square pattern overa transparent sheet to display a series of images selected from acomposite of individual images. The transparent sheets are fullydeveloped with several different appearances making up the visualdisplay. A drive motor is utilized to drive a cam and cam follower tomove the grid. The mechanical confrontation between the cam follower andthe cam on the drive motor is loose and lacks precision. A device ofthis general type is shown in U.S. Pat. No. 4,306,226 to Swarbrick.Because of the lack of precision in relative movement, the apertures inthe grid are made smaller than the pixels of the transparent sheet toaccount for errors in grid placement when the grid is shifted over thetransparent sheet.

Devices have been proposed which include translucent image screens madeup of mosaics of discrete images formed by interlaced translucent pixelswhich are arranged in uniform groups. Pixels corresponding to an imageoccupy the same relative position in each group. The image screen iscovered with an opaque screen having a uniform pattern of transparentapertures. The opaque screen blocks back lighting from shining throughthe image screen except through the apertures. The uniformly patternedapertures are then aligned with pixels which correspond to an image andthe image is thereby displayed by the back lighting shining through theimage screen and the apertures. The opaque screen is selectively shiftedon the image screen such that the apertures align with the pixels of adifferent image. A device of this general description is shown in U.S.Pat. No. 4,897,802 to Atkinson et al. Notwithstanding the excellentoperational characteristics of the aforementioned patent, it isdesirable to have a better drive system enabling precise and accurateregistration between such an image screen and the opaque screen.

SUMMARY OF THE INVENTION

The present invention is directed to a sequential picture selectionapparatus with precise rotary drive positively coupled to remoteeccentric drives for continued rotation in one direction to achieveforward travel through a closed loop path. The apparatus includes ahousing having a light source mounted rearwardly therein and shiningforwardly through a window and a platen over which a mosaic of sets oftiny pixels is movably mounted and to be sandwiched between such platenand a stationary grid sheet having apertures which are simultaneouslyregisterable with pixels of corresponding sets to collectively projectdiscrete images. A precision stepper drive motor is coupled with atleast one eccentric which engages and drives the mosaic sheet through apredetermined closed loop path to sequentially move the mosaic sheetrelative to the grid in a manner to sequentially register the respectiveindividual pixels of the sets with the respective apertures. A controldevice is provided which connects with a stepper drive motor and isoperative to stop the drive motor in dwell positions with the respectivecorresponding pixels of the pixel sets registered with the respectiveapertures. In the preferred embodiment, the stepper motor is operativeto be reset to a predetermined home position during each revolution. Thestepper motor drive shaft may be coupled with the eccentrics by means oftiming belts.

Other features and advantages of the invention will become apparent fromthe following detailed description, taken in conjunction with theaccompanying drawings, which illustrate, by way of example, the featuresof the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a display apparatus according to thepresent invention;

FIG. 2 is a top plan view, in enlarged scale, partially cut away, of thedisplay apparatus shown in FIG. 1 showing a frame, a platen, a filmsheet, and a grid sheet;

FIG. 3 is a cross-sectional view, in enlarged scale, taken along line3--3 of FIG. 2;

FIG. 4 is a vertical sectional view, in enlarged scale, taken along line4--4 of FIG. 2;

FIG. 5 is a horizontal sectional view taken along line 5--5 of FIG. 4;

FIG. 6 is a perspective view, in enlarged scale, of the stepper drivemotor included in the apparatus shown in FIG. 1;

FIGS. 7-10 are diagrammatic views of the eccentric drive of FIG. 4showing the eccentric drive and the film sheet in four different stoppositions respectively;

FIGS. 11-18 are diagrammatic views of pixel patterns incorporated in agrid and film sheet of a second embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

As shown in the drawings for purposes of illustration, the invention isembodied in a precise rotary drive for shifting a translucent film sheetin one direction around a closed loop pattern under an opaque grid sheethaving a plurality of display apertures to sequentially display discreteimages formed in the film sheet.

The film sheet comprises pixels of discrete images interspersed withpixels of other discrete images. The images are sequentially displayedby relative movement between the film sheet and the grid sheet such thatthe display apertures of the grid sheet precisely align with pixelscorresponding to a particular image to be displayed. The film sheet isilluminated only through precisely located apertures in the grid sheetfor projection only through the pixels which are aligned with theapertures. When the grid apertures register with a specific set ofpixels, one discrete image is displayed.

The film sheet is moveable on a platen securely mounted on a framehoused in an illuminated display housing. The platen is formed of asturdy translucent surface with circular indentations disposed thereinfor receipt of two remote cylindrical heads. The film sheet hasfollowers formed therein for pivotal receipt of pins movably mounted onand displaced from a central axis of each remote head.

In accordance with the present invention, a stepper motor includes amotor shaft having two linked sprocket wheels non-rotatably mountedthereon. Each sprocket wheel is coupled through a respective toothedtiming belt to an eccentric drive including an eccentrically locatedpin. As the eccentric drives are controllably rotated through a patternof dwell points, the respective pins drive the film sheet about apredetermined closed loop pattern stopping at precise, discretepositions.

Referring to FIGS. 1-3, the apparatus of the present invention includes,generally, an open center square frame 20 for setting in a housing toform part of such housing and formed centrally with a window 21 overwhich is mounted an arcuately shaped transparent platen 30 forprojection therethrough of light from fluorescent tubes 31. Mounted atthe diagonally opposite corners of the frame are respective eccentrics,generally designated 34 and 36, which are operative to shift atranslucent photographic mosaic film sheet 32 through a circular pathunderneath a grid sheet, generally designated 114. The respectiveeccentrics 34 and 36 are coupled with a pair of sprockets 50 and 52(FIG. 6) fixedly attached to the drive shaft 46 of a step motor,generally designated 44, by means of timing belts 90 and 92. A controlcircuit housed in a control box 62 (FIG. 6) is connected with the stepmotor 44 to stop the step motor at dwell points where correspondingpixels in the film sheet 32 cooperating to form the image to beprojected are positioned in alignment with the respective apertures ofthe grid screen 114.

The platen 30 may be constructed of translucent acrylic material and isconvexed upwardly to cause the tension pins 22 and 24 to draw the gridsheet 114 down firmly on the image sheet 32 to apply slight tensioningthereto and maintain the image sheet relatively firmly pressed againstthe surface of the platen to maintain it to prevent puckers, ripples orwaves therein which might negatively affect the projection of lightthrough the pixels and apertures.

Referring to FIG. 4, the eccentrics 34 and 36 are mounted from the frame20 by means of mounting stems 78. Such eccentrics are in the form ofcylindrical heads, generally designated 70, carried from the stems andformed in their exposed ends with respective eccentrically locatedcounterbored bore defining cavities 86 offset from the rotational axisof the respective wheels by a distance corresponding with one-half thecross-sectional dimension of a pixel. Press fit into the cavity 86 isthe outer race of a ball bearing assembly generally designated 102.Press fit into the center race of such ball bearing are respectiveeccentric pins 100 which project outwardly beyond the projecting ends ofthe respective heads 70 to be received in press fit relation witheccentric drive holes 108 formed at diagonally opposite corners of thefilm sheet 32. Formed in the bottom of the respective heads 70 arerespective bores 82 into which bronze bushings 88 are press fit whichprovide for free rotation on the respective mounting stems 78. Formed inthe periphery of the respective heads 70 at the bottom portion thereofare respective toothed grooves 76 which define sprockets for meshingwith the teeth of the respective timing belts 90 and 92.

The grid sheet 114 is formed adjacent to its diagonally opposite cornerswith respective clearance bores 71 (FIG. 4) which overlie the respectiveeccentrics 34 and 36 and provide clearance for orbiting of therespective eccentric drive pins 100 which engage and drive the filmsheet 32.

Referring to FIG. 3, mounted centrally on the sides of the framesdefining the run for the respective timing belts 90 and 92 arerespective guides 38 which deflect the medial runs of the respectivebelts upwardly to cause the belts leading away from the respectivesprockets 76 to assume a straight run out from such sprockets andmaintain such belts threaded over the respective sprockets.

The rotary stepper motor 44 (FIGS. 1 and 6) is a conventional DC motorhaving a cylindrical body 45 mounted to a corner of the frame 20. Thestepper motor shaft 46 (FIG. 6) protrudes from one end of the steppermotor body 45 to project through the frame and through a mountingbracket 48 (FIG. 1). First and second sprockets 50 and 52 (FIGS. 1 and6) are mounted on the projecting end of the motor shaft 46. The twosprocket wheels 50 and 52 are keyed to the motor shaft 46 by respectiveset screws. When the screws are tightened, the sprocket wheels 50 and 52are locked.

A timing wheel 54 (FIG. 6) is mounted on a second end of the motor shaft46 on the back side of the motor 44. The timing wheel is a circularrotor disk. The disk is formed with a radial timing notch 56 forselected projection therethrough of an infrared timing beam.

The stepper motor 44 (FIGS. 1 and 6) rotates the motor shaft 46counterclockwise. The motor shaft 45 stops at four dwell positions alongthe 360° circuit, with 0° being 12 o'clock high. Each dwell position isseparated by 90°. Position 1 is 45°. Position 2 is 315°. Position 3 is225°. Position 4 is 135°. The stepper motor 44 rotates the motor shaft46 through 200 precise steps per revolution, each being 1.8 degrees ofrotation. Fifty stepped increments rotate the motor shaft the required90° between the dwell positions. The dwell duration at each dwellposition is 0.5 seconds and up. The drive motor 44 circuitry isresponsive to control pulses to rotate the drive shaft 46 at a precisespeed to advance and stop at the 200 discrete precise positions perrevolution. The stepper motor is electrically coupled to a stepper motorcontroller 62. The motor shaft 46 is advanced one step for each commandpulse received by the drive motor 44.

A miniature infrared transmitter 58 and a receiver 60 (FIG. 6) aremounted beneath the body 45 of the stepper motor 44 on opposite sides ofthe timing wheel 54 so that infrared radiation emissions are directed atthe timing wheel to project through the notch 56 once each revolution.The infrared receiver 60 is responsive to receipt of infrared radiationfrom the infrared transmitter 58 to pass a receiver signal to thestepper motor controller 62.

Control buttons (not shown) are mounted on the display housing controlpanel to control the stepper motor controller circuitry enabling anoperator of the display apparatus to select the precise rotation speedof the motor driven motor shaft 46 (FIG. 6), the number and location ofprecise dwell positions within a turn cycle, and the dwell duration. Thestepper motor controller 62 includes a microprocessor driven circuitboard. A drive control program stored as firmware within themicroprocessor controls the stepper motor to generate command pulses ata predetermined time and rate. The drive control program is responsiveto commands from the user interface control buttons coupled to thestepper motor controller 62.

The stepper motor controller 62 includes a memory and a counter to countthe steps moved by the rotating motor shaft 46. After the motor shaftcompletes the 200 steps of a complete revolution, the stepper motorcontroller generates a reset signal and senses to determine if thetiming wheel slot 56 has physically completed a precise revolution andbeen returned to its home position, position one. The control programcontrols a feedback circuit portion of the circuit board utilizing afind home routine. The feedback circuit is responsive to the resetsignal to control the infrared transmitter 58 to transmit to an infraredreceiver 60 as the motor 44 is commanded by the controller 62 to rotatethe timing notch 56 on the timing wheel 54 through a 360° rotation. Thestepper motor controller 62 attempts to detect the receiver signal toinsure that the motor shaft 46 is lodged at home position. If thereceiver signal is not detected, the motor shaft 46 continues to rotatethe timing wheel rotor 54. When the leading edge of the notch 56 movesbetween the transmitter 58 and the receiver 60, the infrared signal isreceived and that position of the motor shaft is stored as the correcthome position in memory.

It is important that the timing belts 90 and 92 (FIG. 1) are inelasticand are formed with respective sets of teeth that mesh with therespective teeth of drive sprockets 50 and 52 and respective driversprockets 76 of the eccentrics 34 and 36. Since this linkage is reliedon to positively translate the precise positioning of the drivesprockets 50 and 52 to the respective eccentrics 34 and 36 without anyother peripheral stops, it is important that the connection be precisewithout undue play or elasticity on the connection.

The grid film sheet 32 may be of the type shown in U.S. Pat. No.4,897,802 to Atkinson and assigned to the assignee of the rights in theinstant invention. The sheet is photographically prepared to form fourdiscrete images formed from sets of pixels corresponding to the discreteimage interlaced with other sets of pixels corresponding to otherdiscrete images. Each pixel 109 of the set of four is square, having adimension of 0.039 inches (1 mm) on a side. Each square four pixel grouphas a dimension of 0.078 inches on a side. Referring to FIGS. 7-10, theeccentrics 34 and 36 are constructed with respective drive pins havingan eccentricity equal to one-half the width of the respective width ofthe respective square pixels 109 such that the respective eccentric pinsare orbited through a circle having a diameter equal to the width of afull square. The image components of the respective images may be brokendown to pixel positions depicted in FIGS. 7-10 as positions 1, 2, 3, and4. Referring to FIG. 1, with the grid sheet 114 in the position with therespective apertures in alignment with the corresponding pixels ofposition "one" of each of the four pixel sets, the composite imagecorresponding with the composite of pixels in position "one" will bedisplayed. It will be appreciated that the film sheet 32 is then rotatedthrough a circular pattern 111 (FIG. 7) in the counterclockwisedirection resulting in such sheet being rotated upwardly and to the leftfrom position number "one" 113 to move 90° on the pattern 111 to thesecond position 115 where it may again dwell to display the compositeimage corresponding with the pixels in position number "two" (FIG. 8).The process is then continued for the dwell positions 119 and 121corresponding with the pixels in position numbers "three" and "four"depicted in FIGS. 9 and 10, respectively. The arc of movement of a pixelfrom one dwell position to the next along the circular pattern 111 issmall, approximately 0.2 mm. This ensures that non-selected pixels arenot momentarily illuminated as the film sheet is moved along thecircular pattern 111. In the preferred embodiment, the film sheet 32 issprayed on its opposite sides with a dry lubricant 107 such as a Teflonlubricating film. With this arrangement, the eccentrics 34 and 36 may becoupled directly to such film by, for instance, the eccentricallymounted pins 100 to drive the relatively light film sheet about its pathapplying a relatively small force of only about 200 grams.

The square photographic grid sheet 114 (FIGS. 2, 3 and 4) may be of thetype shown in the Atkinson patent and has photographically imposedhorizontal and vertical opaque members regularly spaced to formapertures. The dimensions of each aperture corresponds to the dimensionsof each pixel. The square photographic grid sheet 114 overlies the filmsheet 32 and the platen 30 (FIGS. 2, 3 and 4). The grid sheet 114 hasglued to its opposite sides angle handle bars 116 and 118 (FIG. 2)having respective diamond shaped mounting holes 120 and 122 formed inthe respective horizontal flange thereof. The receiving holes 120 and122 receive the respective retaining pegs 22 and 24.

The mounting pegs 22 and 24 are floatingly carried from respectivemounting blocks 121 and 123 mounted under the frame 20 and projectupwardly through oversize slots in such frame. The peg 22 is biasedoutwardly away from the platen 30 by a spring 125 (FIG. 3) to thusmaintain a slight tension on the flexible grid sheet 114.

Referring to FIG. 2, an adjustment mechanism is provided to floatinglymove the grid sheet 114 with respect to the stationary underlying platen30 (FIG. 2). A pair of knurled thumb wheels 127 and 129 threadedlyengage floating blocks on which the respective pegs 22 and 24 aremounted so that lateral adjustment may be made by rotating such knob.

A vertical adjustment knob 131 is carried from the bottom side of theframe 20 (FIG. 2) for manipulating the pin 24 up and down to draw thegrid sheet 114 relative to the floating top peg 22 to shift the gridsheet vertically.

Synchronization of the relationship between the stepper motor and theeccentric drives is a final step in the manufacturing of the displayapparatus. The set screws on the motor shaft are loosened freeing thesprocket wheels 50 and 52 (FIG. 6) to free wheel. The belts 90 and 92are installed and the stepper motor shaft 46 driven to its homeposition, position number one, corresponding to the position of the slot56 in the timing wheel 54 (FIG. 6) disposed in alignment between theinfrared transmitter 58 and receiver 60. The stepper motor controller 62recognizes and records this position. The sprocket wheels 50 and 52 areeach manually rotated to a position 45 degrees counterclockwise from 12o'clock high, corresponding to home position number "one" and the setscrews are tightened locking the sprocket wheels 50 and 52 on the motorshaft.

To operate the advertising display apparatus of the present invention,the user opens the housing cover of the display apparatus and removesthe grid sheet 114 from the retaining pegs 22 and 24. A film sheetcontaining the desired images is then placed in overlying relation onthe platen 30. The follower holes 108 (FIG. 4) of the film sheet arereceived in tight fit over the pins 100 of the eccentric drives 34 and36. The user then mounts the grid sheet 114 over the selected film sheet32 by fitting the top opening 120 over the peg 22 and drawing such pegtoward the lower peg 24 to then snap the lower opening 122 over the peg24. The adjustment knobs 127, 129 and 131 are then adjusted to float thegrid sheet into position focusing the apertures in alignment over therespective corresponding pixels 109 of the sets of pixels.

The user then turns the power switch on the control panel to "on". Thefilm sheet is automatically driven to position "one", home position. Theuser selects the run mode of operation by depressing a button on thecontrol panel. The user then selects the number of advertising images,for instance four, and programs the display time of each imagecorresponding to the dwell duration of the film sheet at each dwellpoint. The user selects automatic control of the advance rate of themotor shaft by the stepper motor controller. Alternatively, the advancerate is also controllable and selectable by the user.

It will be appreciated that the stepper motor 44 will then advance inincrements to transmit the rotative motion through the drive sprocketsto the timing belts 90 and 92 and to the sprockets of the eccentrics 34and 36 to advance such eccentrics precisely 90° about the circularpattern 111. At each of the dwell points 113, 115, 119 and 121 (FIGS.7-10), the stepper motor will stop and dwell to provide for momentaryviewing of the composite image projected from the corresponding sets ofpixels. This precise advancement is relatively noise free and results inrelatively minor wear on the moving components. Additionally, since thebelts 90 and 92 and sprockets 76 (FIG. 4) move in the same rotativedirection without reversing, any relative wear between such sprocketsand the belts will be on the same sides of the respective teeth so thatthe resultant wear will have little or no effect on the precision withwhich the drive sprockets drive the eccentric slave sprockets.

In an alternate embodiment, the film sheet is photographicallyconfigured to form six discrete images (FIGS. 11-18). Each of the sixdiscrete images is a composite of a set of pixels. The set of pixels areinterlaced with other sets of pixels corresponding to other discreteimages (FIG. 18). The pixels of the sets are arranged in uniform groups130 (FIG. 11) of pixels such that pixels from any one image are locatedin corresponding positions in each group. Each pixel 132 of the group isof hexagonal shape. Each side of the hexagonal pixel is of dimension 0.5mm in length. The area of each hexagonal pixel is 0.6495 mm². The groupsof pixels in the six image embodiment are of hexagonal shape with sixpixels, each corresponding to one of the six discrete composite images,being disposed around the perimeter of the hexagonal group 130. Withineach hexagonal group of pixels, there is a null point 134 (FIG. 11)containing no data. In this embodiment, the apertures of the overlyinggrid sheet are hexagonal and correspond to the dimensions of thehexagonal pixels.

The stepper motor is programmable to sequentially rotate the motor shaftcounterclockwise to six dwell positions in the six image embodiment.With 0/360 degrees being high noon, position one is 45 degreesclockwise. Position two is 345 degrees. Position three is 285 degrees.Position four is 225 degrees. Position five is 165 degrees. Position sixis 105 degrees. Six pixels corresponding to six discrete images areshown in sequence within one hexagonal aperture of the grid sheet.Movement of the film sheet by the eccentric drives to position onereveals a first pixel of each six pixel group within the film sheet(FIG. 12). Movement of the film sheet by the eccentric drives to asecond position reveals a second pixel of each pixel group (FIG. 13).Movement of the film sheet by the eccentric drives to a third positionreveals a third pixel of each six pixel group (FIG. 14). Movement of thefilm sheet to a fourth position reveals a fourth pixel of each six pixelgroup (FIG. 15). Movement of the film sheet to a fifth dwell positionreveals a fifth pixel of each six pixel group (FIG. 16). Movement of thefilm sheet to a sixth and final position of the sequential circuitreveals a sixth pixel of each six pixel group within the film sheet(FIG. 17).

It will be appreciated to those skilled in the art that numerousdifferent configurations for the pixels and sets of pixels may beadopted wherein the pixels themselves may be located on a path definedby a continuous loop about which the eccentrics may dictate travel ofthe film screen.

From the foregoing, it will be appreciated that the improved displayapparatus associated with the present invention provides a preciseadvancement of a mosaic film sheet along a predetermined closedsequential loop registering discrete images within the mosaic withapertures defined by an overlying grid sheet to project the images. Theimproved display apparatus employs a controllable stepper motorpositively coupled to eccentric drives to move the film sheet throughits circuit precisely stopping at programmed dwell points withoutslippage or lag. This allows registration of the entire pixels withineach pixel set of the film sheet within equally dimensioned apertures inthe grid sheet giving a higher resolution image and more precisealignment than known before.

While a particular form of the invention has been illustrated anddescribed, it will be apparent that various modifications can be madewithout departing from the spirit and scope of the invention.

What is claimed is:
 1. An advertising display apparatus for displaying aseries of discrete images in sequence, and comprising:a housingincluding an illumination source; a platen overlying said illuminationsource and formed with a central window for projection of light fromsaid source; a film sheet overlying said platen and formed by aplurality of independent images, each formed by spaced apart sets of aselected number of predetermined sized pixels interlaced with and spacedfrom one another to, in each said set, form a common pattern withcorresponding pixels of each said set correspondingly located and thecorresponding pixels of each set disposed at selected dwell points alonga predetermined rotary path, said film sheet being moveable through saidpredetermined rotary path; a grid sheet overlying said film sheet andformed with a pattern corresponding with the location and size of saidselected number of predetermined sized pixels and including transparentapertures repetitively interlaced in said pattern corresponding with thecorrespondingly located pixel of each said set; a step drive motormounted in said housing and including a drive sprocket wheel; a pair ofspaced apart eccentric drives mounted from said housing, engageable withsaid film sheet, and operative to, upon rotation thereof, translate saidfilm sheet through said predetermined rotary path to advance said setsof pixels to sequentially register with said corresponding apertures; apair of non-distensible coupling links coupling said sprocket wheel tosaid eccentric drives to positively rotate said eccentric drives inunison with rotation of said sprocket wheel; and a control device foradvancing said step drive motor in predetermined increments sufficientto cause said coupling links to incrementally and sequentially advancesaid eccentric drives in incremental amounts sufficient to shift saidfilm sheet through said predetermined rotary path to said dwell pointsto cause said coupling links to positively stop said film sheet at therespective said dwell points with said apertures aligned over therespective corresponding pixels of said sets.
 2. A display apparatus asrecited in claim 1 wherein:said step drive motor includes a DC motor, anelectrical circuit within said DC motor operative to control said stepdrive motor to rotate said drive shaft at a predetermined rate and tostop at said selected dwell points; and said control device includesmeans for selecting said predetermined rate and said selected dwellpoints.
 3. A method of displaying an image from a film sheet formed by aplurality of independent images, each formed by spaced apart sets of aselected number of predetermined sized pixels interlaced with and spacedfrom one another to, in each set, form a common pattern withcorresponding pixels of each said set correspondingly located and thecorresponding pixels of each set disposed at selected dwell points alonga predetermined rotary path adjacent a grid sheet formed with a patterncorresponding with the location and size of said selected number ofpredetermined sized pixels and including transparent aperturesrepetitively interlaced in said pattern corresponding with thecorrespondingly located pixel of each said set, said method comprisingthe steps of:providing a display apparatus including a housing with anillumination source, a platen having a window, an eccentric drivemounted on said housing, a step drive motor coupled to said eccentricdrive, and a control device for advancing said drive motor incrementallyfor driving said eccentric drive in a predetermined rotary path;mounting said film sheet movably on said platen; anchoring said gridsheet on said housing over said platen; and connecting said film sheetto said eccentric drive, and actuating said step drive motor to drivesaid eccentric drive directly in one direction to sequentially advancesaid film sheet through a predetermined rotary path to sequentiallyalign said grid sheet apertures with the corresponding pixels of saidsets, and stopping said step drive motor at said dwell points to stopsaid film sheet with said corresponding pixels of said sets in alignmentwith said grid sheet apertures.
 4. An advertising display apparatus fordisplaying a series of discrete images in sequence, and comprising:ahousing including an illumination source; a platen overlying saidillumination source and formed with a central window for projection oflight from said source; a film sheet overlying said platen and formed bya plurality of independent images, each formed by spaced apart sets of aselected number of predetermined sized pixels interlaced with and spacedfrom one another to, in each set, form a common pattern withcorresponding pixels of each said set correspondingly located and thecorresponding pixels of each set disposed at selected dwell points alonga predetermined rotary path, said film sheet being moveable through apredetermined path including selected dwell points; a grid sheetoverlying said film sheet and formed with a pattern corresponding withthe location and size of said selected number of predetermined sizedpixels and including transparent apertures repetitively interlaced insaid pattern corresponding with the correspondingly located pixel ofeach said set; and a driver directly coupled to said film sheet andoperative to shift said film sheet through said predetermined rotarypath to advance said sets of pixels to sequentially register with saidgrid sheet apertures.
 5. A display apparatus as recited in claim 4wherein said platen includes a curved surface, and having:tensioningmeans anchoring said grid sheet under tension to said housing inoverlying relation to said film sheet to hold said film sheet to saidcurved surface of said platen.
 6. A display apparatus as recited inclaim 4 further including:a lubricant coated on said film sheet forreducing the coefficient of friction of said film sheet.
 7. A displayapparatus as recited in claim 4 wherein:said film sheet is formed with apair of spaced apart bores; and said driver includes a pair of spacedapart mounting pins moveable through said predetermined rotary path andremovably engageable in the respective said bores.
 8. A displayapparatus as recited in claim 4 wherein:said film sheet is furtherformed with said sets of pixels arrayed so that said rotary path isabout 1 mm in diameter; and said eccentric drive is configured to orbitsaid film sheet in a circle having a diameter of substantially 1 mm. 9.A display apparatus as set forth in claim 4 wherein:said film sheet setsof pixels are arranged in a square pattern; and said eccentric drive isoperative to, upon actuation of said drive motor, cause relative rotarymovement between said grid sheet and said film sheet.
 10. A displayapparatus as set forth in claim 4 wherein:said film sheet sets of pixelsare arranged in a predetermined circular configuration; and saideccentric drive is operative to relatively translate said film sheet andsaid grid sheet through a circular path corresponding with saidpredetermined circular configuration.
 11. A display apparatus as setforth in claim 10 wherein said pixels are arranged in sets of sixconfigured in a hexagonal pattern; andsaid control device is operativeto stop said drive motor when said eccentric drive relatively positionssaid film and grid sheets at respective dwell points corresponding withthe respective pixel arrangement of said hexagonal pattern.
 12. Adisplay apparatus as recited in claim 11 wherein:said eccentric drive isoperative to relatively translate said film sheet and said grid sheet ina circle.
 13. An advertising display apparatus for displaying a seriesof discrete images in sequence, and comprising:a film sheet formed by aplurality of independent images, each formed by spaced apart sets of aselected number of predetermined sized pixels interlaced with and spacedfrom one another to, in each set, form a common pattern withcorresponding pixels of each said set correspondingly located, saidpattern defining a plurality of selected dwell points along apredetermined rotary path, and the corresponding pixels of each setdisposed at said selected dwell points; a grid sheet formed with apattern corresponding with the location and size of said selected numberof predetermined sized pixels and including transparent aperturesrepetitively interlaced in said pattern corresponding with thecorrespondingly located pixel of each said set, said grid sheetcooperating with said film sheet in overlaying parallel proximalrelation to form a masking mechanism for selectively aligning saidapertures with said sets of pixels following said predetermined rotarypath to sequentially form images responsive to relative rotary movementtherebetween, said apparatus comprising: a housing including an anchordevice for fixedly mounting said masking mechanism; an eccentric drivemounted on said housing, engageable with said masking mechanism, andoperative to, upon rotation thereof in one direction, cause relativerotary movement between said grid sheet and said film sheet through saidpredetermined rotary path to register said apertures sequentially oversaid corresponding pixels; a step drive motor mounted on said housingand including a drive shaft advanceable in discrete precise steps, saiddrive shaft having an initial home position; a coupling device couplingsaid drive shaft directly to said eccentric drive for rotation in onedirection to rotate said eccentric drive; and a control device foradvancing said step drive motor in predetermined increments sufficientto cause said coupling device to incrementally and sequentially advancesaid eccentric drive in incremental amounts sufficient to cause relativerotary movement between said grid sheet and said film sheet through saidpredetermined rotary path to said dwell points to cause said couplingdevice to positively stop relative movement of said film and grid sheetsat the respective said dwell points with said apertures aligned over therespective corresponding pixels of said sets.
 14. A display apparatus asrecited in claim 13, that includes:a platen mounted in said housing andformed with a window for projection of light to intersect with saidmasking mechanism; and a light source for generating light forprojection through said window.
 15. A display apparatus as recited inclaim 13, wherein:said anchor device includes a pair of anchor pegsmounted on either side of said housing and one of said pegs being springloaded outwardly away from the other of said pegs; and said maskingmechanism includes anchor devices disposed on the opposite sidesthereof, including mounting holes for fitting over the respective saidanchor pegs.
 16. A display apparatus as recited in claim 13 wherein saideccentric drive includes:a cylindrical wheel formed with an outwardlyfacing surface and rotatable about a central axis, said wheel includingan eccentrically located bearing cavity bored eccentric to said centralaxis a distance corresponding substantially to one-half the width ofsaid pixels and a mounting pin centrally mounted rotatably in saidbearing cavity and projecting therefrom to engage said maskingmechanism.
 17. A display apparatus as recited in claim 13, furthercomprising:a transmitter mounted adjacent said step drive motor totransmit an index signal; a receiver mounted adjacent said transmitterin spaced relation to form therebetween a path to receive said indexsignal when transmitted along said path and operative in responsethereto to generate a receiver signal to be communicated to said controldevice; a circular index wheel mounted on said drive shaft andprojecting in said path to movably block transmission of said indexsignal along said path and including an index notch for passing saidindex signal along said path; said control device is electricallycoupled to said step drive motor and operative to transmit a commandpulse thereto to advance said drive shaft one of said discrete precisesteps; a memory in said control device; a counter in said control devicefor counting each said command pulse passed to said step drive motor andresponsive to a predetermined number of said command pulses being passedto said step drive motor to generate a reset signal; a controller insaid control device responsive to said reset signal to generate atransmit signal; said transmitter is responsive to said transmit signalto generate said index signal; a logic circuit in said control deviceresponsive to both said reset signal and to the absence of said receiversignal to generate a find home signal; a find home circuit in saidcontrol device responsive to said find home signal to generate saidcommand pulse to be communicated to said step drive motor; said seepdrive motor is responsive to said command pulse to rotate said indexwheel; a detector circuit in said control device responsive to both saidfind home signal and said receiver signal to terminate said commandpulses to said step drive motor and to generate a stop signal; and arecorder in said control device responsive to said stop signal to recordthe position of said drive shaft in said memory as a new home positionof said drive shaft.
 18. A display apparatus as recited in claim 17further comprising:a lubricant coated on said masking mechanism forreducing the coefficient of friction thereof.
 19. An advertising displayapparatus for displaying a series of discrete images in sequence, andcomprising:a film sheet formed by a plurality of independent images,each formed by spaced apart sets of a selected number of predeterminedsized pixels interlaced with and spaced from one another to, in eachset, form a common pattern with corresponding pixels of each said setcorrespondingly located and the corresponding pixels of each setdisposed at selected dwell points along a predetermined rotary path,said film sheet formed with a pair of mounting holes spaced apart apredetermined distance; a grid sheet formed with a pattern correspondingwith the location and size of said selected number of predeterminedsized pixels and including transparent apertures repetitively interlacedin said pattern corresponding with the correspondingly located pixel ofeach said set, and including anchor apertures disposed on its sides; ahousing including an anchor device to engage said anchor apertures forfixedly mounting said grid sheet; a platen for supporting said filmsheet; an eccentric drive including a cylindrical wheel formed with anoutwardly facing surface and rotatable about a central axis, said wheelincluding an eccentrically located bearing cavity bored eccentric tosaid central axis a distance corresponding substantially to one-half thewidth of said pixels and a mounting pin centrally mounted rotatably insaid bearing cavity and projecting therefrom to engage said film sheetand mounted on said housing, engageable with said film sheet, andoperative to, upon rotation thereof in one direction, translate saidfilm sheet through said predetermined rotary path to selectively alignsaid apertures over the selected corresponding pixels of said sets; astep drive motor mounted on said housing and including a drive shaftadvanceable in discrete precise steps, said drive shaft having aninitial home position; a coupling device coupling said drive shaftdirectly to said eccentric drive for rotation in one direction to rotatesaid eccentric drive; and a control device for advancing said step drivemotor in predetermined increments sufficient to cause said couplingdevice to incrementally and sequentially advance said eccentric drive inincremental amounts sufficient to shift said film sheet through saidpredetermined rotary path to cause said coupling device to positivelystop said film sheet with said apertures aligned over the respectivecorresponding pixels of the respective said sets.
 20. A displayapparatus as recited in claim 19 wherein:said eccentric drive includes apair of spaced apart rotatable wheels mounted on said housing includinga respective eccentrically located mounting pin spaced apart saidpredetermined distance for close fitting receipt in the respective saidmounting holes.
 21. A display apparatus as recited in claim 20wherein:said step drive motor includes a drive shaft mounting a pair ofdrive sprockets and said coupling device includes a pair of inelasticlinks connecting said drive sprockets to the respective said rotatablewheels.
 22. A display apparatus as recited in claim 21 wherein:saidlinks are in the form of a pair of timing belts.
 23. A display apparatusas recited in claim 22 wherein:said drive sprockets are formed withperipheral toothed grooves having sprocket teeth; and said timing beltsare formed with belt teeth configured to mesh with said sprocket teeth.24. A display apparatus as recited in claim 22 that includes:a pair ofguides mounted on said housing and engaged with said timing belts toguide the respective said timing belts onto the respective said drivesprockets.